Bhagavad Gita 6.26 · Yato Yato Nishcharatiयतो यतो निश्चरति मनश्चञ्चलमस्थिरम्।ततस्ततो नियम्यैतदात्मन्येव वशं नयेत् ॥

In this verse the Lord gives the method to control the mind. Just as you drag the bull again and again to your house when it runs out, so also you will have to drag the mind to your point or centre or Lakshya again and again when it runs towards the external objects. If you give good cotton seed extract, sugar, plantains, etc., to the bull, it will not turn away but will remain in your house. Even so if you make the mind taste the eternal bliss of the Self within little by little by the practice of concentration, it will gradually abide in the Self only and will not run towards the external objects of the senses. Sound and the other objects only make the mind restless and unsteady. By knowing the defects of the objects of sensual pleasure, by understanding their illusory nature, by the cultivation of discrimination between the Real and the unreal and also dispassion, and by making the mind understand the glory and the splendour of the Self you can wean the mind entirely away from sensual objects and fix it firmly on the Self.